Liquid dispensing apparatus



June 8, 1965 J. c. DAWSON 7,

LIQUID DISPENSING APPARATUS Filed March 9, 1962 3 Sheets-Sheet 1 39 I I 2/ L9 w 37-- June 8, -1965 J. c. DAWSON LIQUID DISPENSING APPARATUS 3 Sheets-Sheet 2 Filed March 9, 1962 FIG.3.

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United States Patent 3,187,956 LIQUID DISPENSING APPARATUS Joseph Carl Dawson, P.O.Bx 5868, Ferguson 35, M0.

Filed Mar. 9, 1962, Ser. No. 178,731 3 Claims. (CL'ZZZ-ISS) This invention relates to liquid dispensing apparatus, and more particularly to apparatus for dispensing measured dosages of a liquid fumigant or the like.

The invention involves improvements upon the apparatus shown in my U.S. Patent Re. 25,172, reissued'May 15, 1952. In the apparatus shown insaid patent, there is provided a vertical measuring cylinder having an inlet at its lower end and an outlet at its upper end. Liquid under pressure is supplied to the inlet; The cylinder has a valve seat at its upper end, and contains a valve member adapted to sink to the lower end of the cylinder. A delivery hose extends from the outlet and has a manually operable delivery valve at its end. A by-pass having a: restriction therein is provided around the cylinder. When the delivery valve is opened, pressure causes the valve member to rise and force liquid out through the delivery hose, the valve member ultimately engaging the valve seat to cut off delivery from the cylinder. On closing the delivery valve, pres-sure is equalized above and below the valve member via the by-pass, and the valve member sinks back to the lower endof the cylinder. If the delivery valve should not be closed immediately upon seating of the valve member against the valve seat, some liquid may leak on by through the by-pass, and increase the dosage of liquid delivered. In some instances, this may be undesirable, and accordingly, one of the objects of this invention is the provision of an apparatus of the class described which provides for pressure equalization in such manner as to avoid the possibility of delivery of an overdose. Also, in the apparatus shown in said patent, in which return of the valve member is by gravity, an upright arrangement of the measuring cylinder is'in order, and return of the valve member may be slower than desired. Accordingly, a further object of the invention is the provision of apparatus of the class de scribed in which the valve member is positively returned, rather than returned by gravity, which tends to speed up the return and enables the measuring cylinder to be mounted in any desired position, such as in horizontal position. Such a positive return type of device may be used in apparatus with a by-pass such as shown in said patent, if the possibility of a slight overdose is not critical, or'may be used in the improved system of this invention Which-provides for pressure equalization in such manner as to avoid the possibility of an overdose. Still another object of the invention is the provision of means for adjusting the apparatus to deliver different dosages.

Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the followingclaims.

In'the accompanying drawings, inwhich several of various possible embodiments of the invention are illustrated,

FIG. 1 is a view in elevation of a liquid dispensing apparatus of this invention;

FIG. 2 is an enlarged fragment of FIG. 1, with parts broken away andshown in section, showing details of a delivery valve" FIG. 3 is an enlarged fragment of FIG. 1, with parts broken away and shown in section,i-showing details of a measuring cylinder;

FIGg-4 is a view showing modification;

FIG. 5 is a view in elevation of an alternative embodiment of this invention;

- FIG. 6 is an enlarged section taken on line 66 of FIG. 5 showing the measuring cylinder arrangement of FIG. 5 FIG. 7 is an enlarged partial section showing the mess uring cylinder of FIG, 6 used in the FIG. 1 apparatus; and FIG. 8 'is a view showing a modification providing for adjustment to deliver dilierentdosages.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. Referring to FIG. 1 of the drawings, a liquid dispensing apparatus of this invention is shown to comprise a portable support generally designated 1 comprising a base 3, upstanding legs 5, a brace 7, and a carrying handle 9 .extending between the upper ends of the legs 5 Mounted between legs 5 are a pressurized gas (air) supply tank 11 and a tank .13 which may be filled with liquid fumigant. The tanks 11 and 1-3 are adapted to beheld between legs 5 by metal straps. 15. Mounted on the base 3 of the support is an assembly designated in its entirety by the reference character 17 and including a vertical measuring cylinder 19, and an air chamber 21 having its lower end in communication with the lower end of the cylinder 19- Pressure tank 11 is connected to the fumigant tank13 by piping 23 in which is located a pressure regulator 25 and. pressure gauge 27, and a hose 29 extending from the regulator to the upper end of the fumigant tank. Cut.- olfs are provided as indicated at 31 and 33. The pressure tank is adapted to be pressurized by closing the valve 31 and connecting a supply hose (not shown) which is connected to a suitable pressurizing source (also not shown) to an inlet nipple 35. Nipple 35 includes acheck valve adapted to open under pressure in the supply hose.

The measuring cylinder 19 comprises a tube37 having an upper end head 39 and a lower end head 41. The lower end head 41 has an upwardly extending nipple. 43 (FIG. 3) projecting upwardly into the tube, and has a passage 45 for flow of liquid upward through the nipple into the tube. Attached to the lower end head 41 isthe stem of a T 47. A short length of pipe 48 extends from one side of the T 47 and has a T ,49 secured to one end thereof. .Thestem .of T 49 is threaded in the lower end of the air chamber 21. The other .end of T 49 is connected to thelower end of fumigant tank 13 by a pipe 50, an elbow 51. and a pipe 52. A byapasshose 5 3,(whic1 maybe a plastic hose such as a polyethylene hose). is securedat one end thereof to the other side of the T .47. The other end of by-pass hose 53 is 'securedto a manually operable delivery valve 55 which will be hereinafter described.

The upper .end head 39 of .tube 37 is formed with an annular shoulder 57.=w;hich constitutes a .valve seat. An elbow 59 is connected to the upper end head 39. Adelivery hose 61 (which maybe aplastichose such as a polyethylene hose) extends from the elbow 59 to :the manually operable delivery valve 55.

A valve member generally designated 63 is vertically movable inwtube 37 of cylinder 19. This valve .member 63 may :be similar to that shown in U.S. Patent Re. 25,172, comprising a Weight .65 (a body of lead, for example), having at its upper end two 'vertically spaced .horizontal discs .67 and 69 which maybe made of plastic such as polyethylene. The upper disc .67 is a valve. disc engage.- able with shoulder or seat .57 to out ,Ofi .fiow :from the upper .end of the cylinder -19 to the delivery. hose 61. The lower disc fi9lserves as a'pistonwhereby -the..v. alve member 63 is adapted to rise in the cylinder iron an initial position in the lower ended the cylinder (FIG. 3) in response to a pressure drop in thecylinder above the valve member 63. Both discs ,ahavea relatively. loose fit in the cylinderso that thevalve member 63, withoutundue impedance, is adapted to sink to the lower end of the cylinder under the gravity bias of its weight upon equalizadelivery hose 61 to prime the apparatus.

aromas e3 1 a o tion of pressure above and below the valve member 63.

This is beoause'in this embodiment the weight of the volume of the liquid in the cylinderdisplaced by the valve member (which is made of lead, for'example) is less than the Weight of the valve member. Accordingly, the weight of the volume of the liquid in the cylinder displaced by the valve member is such in relation to the weight of the valve member that the valve member tends to move toward the inlet end of the cylinder. At the lowerend of the weight '65 is an inverted cup 71 which covers nipple 43 when the valve member 63 13 at the lower end of the cylinder 19. v

The manually operable delivery valve 55 (FIG. 2) cornprises a valve body 73 threaded into a handle 75. Valve 55is provided with a transfer port 77, a bypass port 79 and a delivery outlet 81. A passage 83 is provided in valve body 73 and is ioounterbored at 35. Threaded into the countenbore 85 is a cup-shaped fitting 87 in which a manually operable button 89 is sl-idably mounted. A

valve member 51 has a stem 13 threaded into the lower end oi button 89. The fitting 87 is provided with ports 95 whichcommunicate with a port 97- in the valve body 73. Port 97 is connected to the delivery outlet 81. The

valve member 91 is biased toward a seat 99 on the bottom of the fitting 87 by a spring 101 extending between the button 89 and the upper surface of the bottom of the cupshaped fitting 87. A second valve member 105 is mounted in passage 83. Valve member .1115 is biased by a spring .1117 towards a seat 109 surrounding the by-pass port 79. [The valve member 105 is adapted to be held against seat 109 by the valve member 91 when the button 89 is pushed downwardly as viewed in FIG. 2.

A delivery nozzle 114 is threaded into a delivery outlet 81. The by-pass hose 53 is connected to the bypass port 79 by a fitting 111. The delivery hose 61 is connected to the transfer port 77 by a fitting 113.

Assuming the pressure tank to be pressurized and the valves 31 and 33 open, operation is as follows:

Liquid under pressure is supplied to bypass ho se 53.

This pressurized liquid forces the valve member 195 in the delivery valve 55 upwardly as viewed in FIG. 2. against the bias of spring 107. The liquid in bypass hose 53 passes through passage 83 and back through port 77 and After the pressure on both sides of the valve member 105 is equalized spring 1117 will force it toward engagement with seat 109.

When the button 89 is manually pushed downwardly as viewed in FIG. 2, communication is established between the transfer port 77 and the delivery outlet 81 and the valve. member 91 is moved down toward valve member 105 to hold the latter against seat 1119 whereby co munication is blocked between ports 77 and 79. With transfer port 77 and outlet 81 in communication, the pressure in the delivery hose 61 is released, and there is a pressure drop in the cylinder 19 above the valve member 63, which at this time is at the lower end of the cylinder 19 with cup 71 covering nipple 43. Accordingly, the valve member 63 is driven upwardly by the'pressure below it and rises to the upper end of the cylinder '19. As it rises, it forces liquid out the upper end of the cylinder 19, through the delivery hose 61 and delivery valve 55 to deliver a measured dose of liquid through the nozzle 114 of the delivery valve 55. Upon rising to the upper end of the cylinder 19, the valve disc 67 engages the seat 57 to cut off delivery of any liquid through the delivery hose 61. As long as button 81! is held down, port 79 is blocked so that no liquid can pass from by-pass hose 53 to the nozzle. Consequently, there is no particular urgency for the operator immediately to release the button upon cut-off of delivery through hose 51. s

' Upon release of the button 89, valve member 91 closes on seat 99 and valve member 105 is released. Pressure from the by-pass hose '53 forces the valve member 105 upwardly as viewed in FIG. 2 to establish communication between the ports 79 and 77. The liquid flows from the byapass hose-53 through the valve 55 and delivery line 61 4,5, to the upward end of the cylinder 19, and the pressure above and below the valve member 63 equalize s, whereupon the valve member 63 sinks to the lower end of the cylinder 19. When it reaches the lower end of the cylinder, the apparatus is ready for the next operation.

With liquid under pressure in the pipe 50, a supply of compressed air is maintained in the air chamber 21 above the liquid in the chamber. This chamber being close to the cylinder 19, the compressed air therein iseft'ective on opening the delivery valve 55 for application of pressure to the liquid at the lower end of the cylinder 19 to offset the inertia of liquid and the loss of head, if any, in the pipe Sit, elbow 5-1 and pipe 52 from the liquid :fumigant tank 13. The air chamber may not be essential when the furnigant tank 13 is'located close to the cylinder 19 as in the embodiment shown in FIG. 1, but would be partioularly useful in a case where the piping or a connecting hose between the tfumigant tank and the cylinder 19 is of such length or is of such character as to cause substantiallossof head.

. FIG. 4 shows a measuring cylinder arrangement which may replace the measuring cylinder 19 shown in FIG. 3. The measuring cylinder 19 in FIG. 4- is inverted or reversed so that the nipple 43 extends downwardly into the tube from the end head 41 and the seat 57 is at the lowercnd of the cylinder. .The T 47 is connected to the end head 41 and is connected on one side to the pipe 48 and on the other side to the by-pass hose 53. The elbow 59, which is at the lower end of the cylinder in the embodiment shown in FIG. 4, is connected to the delivery hose 61. Instead 'of a weighted valve member .63, a floating valve'member 115 is employed. That is, the weight of the liquid displaced by the valve member 115 is greater than the weight of the valve member so that the valve member 115 will rise upon equalization of pressure on both sides thereof. Accordingly, the weight of the volume of the liquid in the cylinder displaced by the valve member 115 is such in relation to the weight of the valve member that the valve member 115 tends to move (rise) toward the inlet end of the cylinder.

The construction shown in FIG. 5 includes the same I support 1, pressure tank 11, fumigant tank 13 and the connections between pressure tank 11 and fumigant tank 13. The lower end of the fumigant tank 13 is connected to a horizontal measuring cylinder 117 by an elbow 119. As shown, a by-pass 121 is provided for the cylins der 117. In theby-pa'ss 121 there is an adjustable valve 123. This may be a conventional needle valve, for ex- 1 ample.

The cylinder 117 comprises a tube 125 having an inlet end127' and an outlet end 129. Aperipheral flange 131 is provided internally of tube 125 adjacent to but spaced inward from the inlet end 127. A nipple 133 is threaded into the outletend 1219 of thetube 125 and extends toward the inlet end 127 .of the tube. The inner end of this nipple constitutes a valve seat135. The outer end of the nipple 133 is connected to one sideof a T 137. The other side of the T 137 is connected to a-delivery hose 139. B y-pass valve 123 has one end secured to an elbow 141 and its other end Connected to the inlet end 127 of the cylinder 117 by a conduit 143. The, other end of elbow 141 is connected to the stern of T 137 to complete the by-pass 121.

A cup-shaped valve member generally designated 145 is movable in the tube 125 of cylinder 117. Valve member 145 is biased toward the inlet end of the cylinder 117by a spring 147 extending' between the bottom of the cup-shaped valve member 145 and the outlet end of the cylinder 117. Spring 147 surrounds the nipple 133.

-1 cylinder-from an initial positiomat the-inletend 'of'the cylinder (illustrated: in; FIG. 6) in: response 1 to a: pressure .drop on the outlet side of the valvememberl45. A hole .149 .is. provided in-the valve member wall so that the V valve member 145, without undue impedance; isadapted in FIG. 5 underthe pressure in thedelivery hose when :the delivery valve is; opened.

=9peration-ofthe embddimentshown in-FIGS. 5 and 6 is ets-follows: p i

The pressure at the -inlet end-of the cylinder- 1 17 -is preferably -regulated to be, for example, about =fifty =to seventy-five --pou-nds per square inch. When such pres- -sure-isemployed, the check valve 157 is one that is adapted toopenunder-about 1b. per sq. inch-pressure in the delivery hose line 139. The bypass valve 123 is opened wide to allow liquid -to" flow 'freely throughthe by-pass 121 to the delivery'hose139 torprime'th'e apparatus. Then the by-pass valve 123 is turned down to provide a restriction in the by-pass 121 such as to effect a pressure drop in cylinder 117 on the outlet side thereof whenever the manually operable delivery valve 151 is operated.

Thus, when the delivery valve 151 is operated, the pressure in the delivery hose 139 is released, and there is a pressure drop in the cylinder 117 on the outlet side of the valve member 145, which at this time is at the inlet end of the cylinder with the open end of thevalve member 145 engaging the flange 131. The restriction provided in the by-pass 121 by valve 123 is sufliciently small to preclude such flow of liquid through the by-pass as would materially reduce this pressure drop. Accordingly, the valve member 145 is driven toward the outlet end of the cylinder 117 by the pressure on the inlet side of the valve member and moves to the outlet end of the cylinder 117. As it moves, it forces liquid out of the outlet end of the cylinder 117 and through the delivery hose 139 to deliver a measured dose of liquid through the nozzle 153 of the delivery valve 151. Upon moving to the outlet end of the cylinder 117, the bottom of the cup-shaped valve member 145 engages the seat 135 to cut off delivery (except for the small amount that may leak through the restriction in the by-pass provided by the valve 123). Upon such cut-oil, the pressure in delivery hose 139 drops below that required to maintain check valve 157 open, and this check valve closes to keep the delivery hose primed, even though the operator should not at once release the lever 155 of the delivery valve 151 to allow it to close. However, the cut-oil is readily sensed by feel so that an alert operator may immediately release the lever 155 to close the delivery valve 151.

With the delivery valve 151 closed, pressure from the elbow 119 bleeds through the restriction in 'by-pass 121 provided by valve 123, and the pressure on the inlet and outlet sides of the valve member 145 equalizes, whereupon the valve member 145 is moved to the inlet end of the cylinder 117 by the spring 147. When the open end of the valve member 145 reaches the flange 131, the apparatus is ready for the next operation.

If positive cut-ofi is desired, the cylinder 117 and spring-returned valve member 145 such as shown in FIG. 6 may be incorporated in the FIG. 1 embodiment in place of the cylinder 19 and gravity-returned valve member 63 shown in FIGS. 1 and 3. FIG. 7 illustrates the cylinder 117 and valve member 145 as they would appear when so substituted in the FIG. 1 embodiment. An elbow 159 connects the fumigant tank 13 to the inlet end of the .cylinder 117. By-pass hose 53 is connected between the -inlet--end of the cylinder 1-17and* the"in1et.port 79of the -manually operable delivery valve -55. Thedelivery hose 61 is connected between the outlet end of cylinder 117 and the'inlet port 77 of-the delivery valve 55; In operation, the FIG. 7 embodiment functions -in substantially 'the-sarne'mann'en-as the embodiments shown in :FIGS.

.1-4. Upon ipushing button 89 downwardly the inlet .port-77 ist plaeedin communication withthe delivery port .81 so as to effeet a pressure drop-on the outlet side of the valve member 145. -Accordingly, the-pressure on the -inlet side of-the valve member -forces the valve member toward-the-outlet end of the cylinder -'117-against=the --return bias of spring 147. When valve member 1453R- ,gages -seat 1-35, 1 delivery through 'thedelivery hose '61 is cutoff. When the button 89 =is'released,'the.=inlet ports 77 and -79 are placed-incommunication to equalize the pressure on both sides-of the valve member 145,where- "upon the valvemembenis-retumedby spring'147 toward and into engagementw-iththe-flange 131.

yIt-will be seen that'in each-of-the embodiments shown :in .FIGS. 3, 4 and -7'the valve member is-biased toward the inlet end-of the cylinder when the pressureon'both :sides of the valve member is substantially equalizedand the valve member moves towards the outlet end of the :cylinder in response *to a pressure drop on theoutlet "side of the valve member.

FIG. 8 shows another possible modification providing for adjustment to vary the amount of liquid delivered. Here a measuring cylinder 19 such as shown in FIGS. 1 and 3 is provided. A valve member 145 such as shown in FIG. 6 may be used, with or without a spring such as shown at 147 in FIGS. 6 and 7. Instead of using a T at the inlet end of the cylinder, there is used a cross fitting 171. One arm of this fitting is coupled to the inlet end of'the cylinder. A packing gland 173 is threaded in the end of the opposite arm of the fitting, and a stop rod 172 extends slidably through the gland. This rod has a handle 175 at its outer end, and reaches axially through nipple 43 into the cylinder 19 (with space around the rod for flow of liquid). The valve member 145 is engageable with the inner end of the rod to determine the retracted position of the valve member, and by loosening the gland, sliding the rod in or out and tightening the gland, the stroke of the valve member 145 may be varied to vary the dosage delivered on a pressure stroke of the valve member 145.

In view of the above, it Will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Apparatus for dispensing measured dosages of a liquid, such as liquid fumigant, comprising a pressure tank for containing pressurized gas, a liquid tank for containing the liquid to be dispensed, a support, said tanks being mounted on said support, a delivery line connecting said pressure tank to said liquid tank, a cylinder mounted on said support, said cylinder having an inlet at one end and an outlet at the other end, a line connected between said liquid tank and said cylinder inlet for supplying liquid uuder pressure to the latter, said cylinder having a valve seat at its outlet end, a movable valve member in the cylinder, resilient means in the cylinder biasing said movable valve member toward the inlet end of the cylinder, said movable valve member being adapted to move toward the outlet end of the cylinder in response to a pressure drop in the cylinder 'on the outlet side of the movable valve member and force liquid through the cylinder outlet, said movable valve member,

gageable with said valve seat to out 01f flow from the outlet end of ,the'cylinder, an inwardly projecting nipple at the outlet end of said cylinder through which liquid flows, said valve seat being on the inner end of said nipple, said resilient means comprising a spring surrounding said nipple and extending between the movable valve member and the outlet endof thecylinder, a delivery hose having a connection to the cylinder outlet, a manually operable delivery v-alve at the outer end of the delivery hose, a by-pass for the movable valve member providing forv communication from the supply hose to the cylinderoutlet on the outlet side of the movable valve member, said by-pass being adapted to effect a pressure drop on the outlet side of saidmovable valve member upon operation of said manually operable valve Whereupon the movable valve member moves toward the outlet. end of the cylinder to force a measured dosage of liquid out through the cylinder outlet and delivery hose, and adapted to provide for equalization of pressure on both sides of the movable valve member after the latter has moved into engagement with said valve seat and said manually operable valve is released, whereupon said resilient means moves the movable valve member to the inlet end of the cylinder. 5

2. Apparatus as set ,forth in claim 1 wherein said cylinder includes a peripheral flange internally thereof adjacent to but spaced from the inlet end of the cylinder, said-movable valve member, Whenthe pressure on both of its sides is equalized, beingiorced into engagement with said flange by said spring.

3. Apparatus as set forth in claim 2 wherein said movable valve member has an opening therein to permit said spring to force the movable valve member toward said inlet end of said cylinder Without undue impedance upon equalization of pressure on both sides of the movable valve member,

References Cited by the Examiner UNITED STATES PATENTS Dawson u 2223 18 RAPHAEL M. ,LUPO, Primary Examiner.

LOUIS I. DEMBO, Examiner. 

1. APPARATUS FOR DISPENSING MEASURED DOSAGES OF A LIQUID, SUCH AS LIQUID FUMIGANT, COMPRISING A PRESSURE TANK FOR CONTAINING PRESSURIZED GAS, A LIQUID TANK FOR CONTAINING THE LIQUID TO BE DISPENSED, A SUPPORT, SAID TANKS BEING MOUNTED ON SAID SUPPORT, A DELIVERY LINE CONNECTING SAID PRESSURE TANK TO SAID LIQUID TANK, A CYLINDER MOUNTED ON SAID SUPPORT, SAID CYLINDER HAVING AN INLET AT ONE END AND AN OUTLET AT THE OTHER END, A LINE CONNECTED BETWEEN SAID LIQUID TANK AND SAID CYLINDER INLET FOR SUPPLYING LIQUID UNDER PRESSURE TO THE LATTER, SAID CYLINDER HAVING A VALVE SEAT AT ITS OUTLET END, A MOVABLE VALVE MEMBER IN THE CYLINDER, RESILIENT MEANS IN THE CYLINDER BIASING SAID MOVABLE VALVE MEMBER TOWARD THE INLET END OF THE CYLINDER, SAID MOVABLE VALVE MEMBER BEING ADAPTED TO MOVE TOWARD THE OUTLET END OF THE CYLINDER IN RESPONSE TO A PRESSURE DROP IN THE CYLINDER ON THE OUTLET SIDE OF THE MOVABLE VALVE MEMBER AND FORCE LIQUID THROUGH THE CYLINDER OUTLET, SAID MOVABLE VALVE MEMBER, UPON MOVING TO THE OUTLET END OF THE CYLINDER, BEING ENGAGEABLE WITH SAID VALVE SEAT TO CUT OFF FLOW FROM THE OUTLET END OF THE CYLINDER, AN INWARDLY PROJECTING NIPPLE AT THE OUTLET END OF SAID CYLINDER THROUGH WHICH LIQUID FLOWS, SAID VALVE SEAT BEING ON THE INNER END OF SAID NIPPLE, SAID RESILIENT MEANS COMPRISING A SPRING SURROUNDING SAID NIPPLE AND EXTENDING BETWEEN THE MOVABLE VALVE MEMBER AND THE OUTLET END OF THE CYLINDER, A DELIVERY HOSE HAVING A CONNECTION TO THE CYLINDER OUTLET, A MANUALLY OPERABLE DELIVERY VALVE AT THE OUTER END OF THE DELIVERY HOSE, A BY-PASS BEING ADAPTED TO EFFECT A PRESSURE VIDING FOR COMMUNICATION FROM THE SUPPLY HOSE TO THE CYLINDER OUTLET ON THE OUTLET SIDE OF THE MOVABLE VALVE MEMBER, SAID BY-PASS BEING ADAPTED TO EFFECT A PRESSURE DROP ON THE OUTLET SIDE OF SAID MOVABLE VALVE MEMBER UPON OPERATION OF SAID MANUALLY OPERABLE VALVE WHEREUPON THE MOVABLE VALVE MEMBER MOVES TOWARD THE OUTLET END OF THE CYLINDER TO FORCE A MEASURED DOSAGE OF LIQUID OUT THROUGH THE CYLINDER OUTLET AND DELIVERY HOSE, AND ADAPTED TO PROVIDE FOR EQUALIZATION OF PRESSURE ON BOTH SIDES OF THE MOVABLE VALVE MEMBER AFTER THE LATTER HAS MOVED INTO ENGAGEMENT WITH SAID VALVE SEAT AND SAID MANUALLY OPERABLE VALVE IS RELEASED, WHEREUPON SAID RESILIENT MEANS MOVES THE MOVABLE VALVE MEMBER TO THE INLET END OF THE CYLINDER. 